The modernization of televisions, monitors, and other display devices has shifted towards flat panel displays, with prevailing design methodology emphasizing slimmer profiles. As a consequence of the shift in design methodology, the volume traditionally used for certain functions are no longer available in flat panel displays, which include liquid crystal displays (LCDs), plasma displays, and light emitting diode (LED) displays. A backlight is a form of illumination used in LCDs to increase visibility in low light conditions, and to increase the brightness of the displayed image. Typically, backlights are placed at the edge of the LCD display and direct illumination across the screen.
Modern LCD screens are typically manufactured to consist of several layers. A backlight is typically positioned near the rear of the LCD screen and used to illuminate pixels of the display. Additionally, a mechanism is generally included that regulates the light intensity of the pixels by varying (via partial or entirely blocking) the amount of light from the backlight that reaches the target pixel.
More advanced LCD displays often include one or more light guides—a specially-designed layer of material (such as plastic) that diffuses the light through a series of unevenly-spaced bumps to provide even lighting throughout the display. However, lower cost LCD displays may not include light guides, and therefore suffer from degradation of image quality as the intensity of the light from the backlights diffuse across the screen, which cause non-uniform brightness. The non-uniform brightness experienced in a display device itself may cause faded and/or low contrast portions which are can negatively impact a user's viewing experience.